// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/base/fake_demuxer_stream.h"

#include <stdint.h>

#include <vector>

#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/single_thread_task_runner.h"
#include "base/threading/thread_task_runner_handle.h"
#include "media/base/bind_to_current_loop.h"
#include "media/base/decoder_buffer.h"
#include "media/base/media_util.h"
#include "media/base/test_helpers.h"
#include "media/base/timestamp_constants.h"
#include "media/base/video_frame.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/size.h"

namespace media {

const int kStartTimestampMs = 0;
const int kDurationMs = 30;
const int kStartWidth = 320;
const int kStartHeight = 240;
const int kWidthDelta = 4;
const int kHeightDelta = 3;
const uint8_t kKeyId[] = { 0x00, 0x01, 0x02, 0x03 };
const uint8_t kIv[] = { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

FakeDemuxerStream::FakeDemuxerStream(int num_configs,
    int num_buffers_in_one_config,
    bool is_encrypted)
    : task_runner_(base::ThreadTaskRunnerHandle::Get())
    , num_configs_(num_configs)
    , num_buffers_in_one_config_(num_buffers_in_one_config)
    , config_changes_(num_configs > 1)
    , is_encrypted_(is_encrypted)
    , read_to_hold_(-1)
{
    DCHECK_GT(num_configs, 0);
    DCHECK_GT(num_buffers_in_one_config, 0);
    Initialize();
    UpdateVideoDecoderConfig();
}

FakeDemuxerStream::~FakeDemuxerStream() { }

void FakeDemuxerStream::Initialize()
{
    DCHECK_EQ(-1, read_to_hold_);
    num_configs_left_ = num_configs_;
    num_buffers_left_in_current_config_ = num_buffers_in_one_config_;
    num_buffers_returned_ = 0;
    current_timestamp_ = base::TimeDelta::FromMilliseconds(kStartTimestampMs);
    duration_ = base::TimeDelta::FromMilliseconds(kDurationMs);
    next_coded_size_ = gfx::Size(kStartWidth, kStartHeight);
    next_read_num_ = 0;
}

void FakeDemuxerStream::Read(const ReadCB& read_cb)
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    DCHECK(read_cb_.is_null());

    read_cb_ = BindToCurrentLoop(read_cb);

    if (read_to_hold_ == next_read_num_)
        return;

    DCHECK(read_to_hold_ == -1 || read_to_hold_ > next_read_num_);
    DoRead();
}

AudioDecoderConfig FakeDemuxerStream::audio_decoder_config()
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    NOTREACHED();
    return AudioDecoderConfig();
}

VideoDecoderConfig FakeDemuxerStream::video_decoder_config()
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    return video_decoder_config_;
}

// TODO(xhwang): Support audio if needed.
DemuxerStream::Type FakeDemuxerStream::type() const
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    return VIDEO;
}

bool FakeDemuxerStream::SupportsConfigChanges()
{
    return config_changes_;
}

VideoRotation FakeDemuxerStream::video_rotation()
{
    return VIDEO_ROTATION_0;
}

bool FakeDemuxerStream::enabled() const
{
    return true;
}

void FakeDemuxerStream::set_enabled(bool enabled, base::TimeDelta timestamp)
{
    NOTIMPLEMENTED();
}

void FakeDemuxerStream::SetStreamStatusChangeCB(
    const StreamStatusChangeCB& cb)
{
    NOTIMPLEMENTED();
}

void FakeDemuxerStream::HoldNextRead()
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    read_to_hold_ = next_read_num_;
}

void FakeDemuxerStream::HoldNextConfigChangeRead()
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    // Set |read_to_hold_| to be the next config change read.
    read_to_hold_ = next_read_num_ + num_buffers_in_one_config_ - next_read_num_ % (num_buffers_in_one_config_ + 1);
}

void FakeDemuxerStream::SatisfyRead()
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    DCHECK_EQ(read_to_hold_, next_read_num_);
    DCHECK(!read_cb_.is_null());

    read_to_hold_ = -1;
    DoRead();
}

void FakeDemuxerStream::SatisfyReadAndHoldNext()
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    DCHECK_EQ(read_to_hold_, next_read_num_);
    DCHECK(!read_cb_.is_null());

    ++read_to_hold_;
    DoRead();
}

void FakeDemuxerStream::Reset()
{
    read_to_hold_ = -1;

    if (!read_cb_.is_null())
        base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
}

void FakeDemuxerStream::SeekToStart()
{
    Reset();
    Initialize();
}

void FakeDemuxerStream::SeekToEndOfStream()
{
    num_configs_left_ = 0;
    num_buffers_left_in_current_config_ = 0;
}

void FakeDemuxerStream::UpdateVideoDecoderConfig()
{
    const gfx::Rect kVisibleRect(kStartWidth, kStartHeight);
    video_decoder_config_.Initialize(
        kCodecVP8, VIDEO_CODEC_PROFILE_UNKNOWN, PIXEL_FORMAT_YV12,
        COLOR_SPACE_UNSPECIFIED, next_coded_size_, kVisibleRect, next_coded_size_,
        EmptyExtraData(),
        is_encrypted_ ? AesCtrEncryptionScheme() : Unencrypted());
    next_coded_size_.Enlarge(kWidthDelta, kHeightDelta);
}

void FakeDemuxerStream::DoRead()
{
    DCHECK(task_runner_->BelongsToCurrentThread());
    DCHECK(!read_cb_.is_null());

    next_read_num_++;

    if (num_buffers_left_in_current_config_ == 0) {
        // End of stream.
        if (num_configs_left_ == 0) {
            base::ResetAndReturn(&read_cb_).Run(kOk,
                DecoderBuffer::CreateEOSBuffer());
            return;
        }

        // Config change.
        num_buffers_left_in_current_config_ = num_buffers_in_one_config_;
        UpdateVideoDecoderConfig();
        base::ResetAndReturn(&read_cb_).Run(kConfigChanged, NULL);
        return;
    }

    scoped_refptr<DecoderBuffer> buffer = CreateFakeVideoBufferForTest(
        video_decoder_config_, current_timestamp_, duration_);

    // TODO(xhwang): Output out-of-order buffers if needed.
    if (is_encrypted_) {
        buffer->set_decrypt_config(base::MakeUnique<DecryptConfig>(
            std::string(kKeyId, kKeyId + arraysize(kKeyId)),
            std::string(kIv, kIv + arraysize(kIv)), std::vector<SubsampleEntry>()));
    }
    buffer->set_timestamp(current_timestamp_);
    buffer->set_duration(duration_);
    current_timestamp_ += duration_;

    num_buffers_left_in_current_config_--;
    if (num_buffers_left_in_current_config_ == 0)
        num_configs_left_--;

    num_buffers_returned_++;
    base::ResetAndReturn(&read_cb_).Run(kOk, buffer);
}

FakeDemuxerStreamProvider::FakeDemuxerStreamProvider(
    int num_video_configs,
    int num_video_buffers_in_one_config,
    bool is_video_encrypted)
    : fake_video_stream_(num_video_configs,
        num_video_buffers_in_one_config,
        is_video_encrypted)
{
}

FakeDemuxerStreamProvider::~FakeDemuxerStreamProvider()
{
}

DemuxerStream* FakeDemuxerStreamProvider::GetStream(DemuxerStream::Type type)
{
    if (type == DemuxerStream::Type::AUDIO)
        return nullptr;
    return &fake_video_stream_;
};

} // namespace media
